Heating system

ABSTRACT

Heating system including a reaction vessel containing a liquid metal mixture and a reservoir containing an oxidizing agent, a supply duct including a control-cock for communicating the oxidizing agent to the vessel for an exothermic reaction with the metal, and an inert gas reservoir communicating through another duct into the supply duct. In the reaction vessel is a centrifuge, with an outlet for the inert gas in the vicinity of the rotary shaft of the centrifuge.

Schrbder et al. 5] MW. 2%, W72

[54] HEATING SYSTEM [56] References Cited [721 inventors: JohannSchriider, Aachen, Germany; Hen- UNITED STATES E TS smells Mam! Beukemg;3,161,192 12/1964 McCormack ..l26/204 MW P t Van WWW, 3,229,681 1/1966Gluckstein..... ...l26/204 both of Emmasmgel, Emdhoven, Nether-3,367,319 2/1968 Carter, Jr... ...126/204 lands 3,385,286 5/1968 Jones...l26/204 73 Assigneez s Philips Corporation, New York, N Y 3,450,1276/1969 Harwood, Jl'. ..126/204 [22] Filed: Sept. 24, 1969 PrimaryExaminer-Charles J. Myhrc [2]] pp No; 860,585 Attomey-Frank R. Trifari[571' ABSTRACT [30] Foreign Application Priority Data Heating systemincluding a reaction vessel containing a liquid Sept. 30, 1968Netherlands ..6813989 metal mixture and a reservoir containing anoxidizing agent, a supply duct including a control-cock forcommunicating the [52 us. 121 ..126/263 Xidiling agent the vessel anemhermic with [51] lm Cl "Fuj 1/00 the metal, and an inert gas reservoircommunicating through [58] another duct into the supply duct. In thereaction vessel is a Field of Search ..126/263, 204; 165/46 centrifuge,with an outlet for the inert gas in the vicinity of the rotary shaft ofthe centrifuge.

pressure prevailing in the reaction vessel. The container communicatesthrough at least one duct including a control-cock with at least onesupply duct connected with the reaction vessel, there being provided, inaddition, at least one second container for a gaseous medium which doesnot react chemically with the liquid in the reaction vessel nor with theoxidizing agent. This second container also communicates through a ductincluding a control-cock with the supply duct, while the reaction vesselhas at least one out-let duct for the supplied gaseous medium includinga controllable stop valve by which the pressure in the reaction vesselcan be regulated.

Heating systems of the aforesaid kind are known; they have the advantageof being capable of supplying heat independently of the surroundings,and without consuming air and without expulsion of flue gases They aretherefore particularly suitable for use at places where an adequatequantity of combustion air is not available and/or at places wherepollution of air by flue gases cannot be tolerated, Heating systems ofthe kind in accordance with the present invention may be employed forsupplying heat to devices in which a working medium performs athermo-dynamic cycle between an expansion space at high temperature anda compression space at lower temperature. Examples of such devices aregas turbines and hot-gas engines. The heating system can supply the heatto the device by establishing a contact between the fluid in the reaction vessel and the heater of the device, which is usually a tubularheat-exchanger traversed by the working medium on its way to theexpansion space. If desired, the heat transfer from the reaction vesselto the heater may be performed with the aid of a heat conveying medium,for example, liquid NaK, which circulates in a duct system whichexchanges heat on the one hand with the reaction vessel and on the otherhand with the heater.

The metal or metal mixture in the reaction vessel may be formed by oneor more of the metals Li, Ca, Na, K, Mg, Al and/or one or more of therare earth metals. These metals and particularly combinations thereofhave the advantage of a comparatively low melting temperature and of agreat development of heat per unit of volume. The oxidizing agent may beformed by a halogen or a halide, particularly fluorine or a fluorinecompound. The oxidizing agent is supplied in dosed quantities to thereaction vessel in which it reacts with the metal or metals whiledeveloping heat. Salts are formed which are solid and/or liquid at theoperational temperature.

The inert gas of the second container can be conducted by opening thecontrol-valve together with the oxidizing agent to the reaction vessel.The supply of inert gas serves to ensure a rate of flow of the medium inthe supply duct opening out in the reaction vessel such that (a) saidduct is cooled by the flow of medium to an extent that the oxidizingagent will not react with the material of said duct, and (b) the liquidof the reaction vessel cannot penetrate into the supply duct. For thispurpose a constant flow of inert gas can be carried on with theoxidizing agent. It is furthermore possible to have carried alongconstantly, the desired quantity of inert gas required for cooling andfor avoiding penetration of liquid. The inert gas furthermore serves tomaintain a constant pressure on the liquid in the reaction vessel, sothat it can be caused to circulate by means of a pump and the oxidizingagent can be supplied to the reaction vessel constantly against the samepressure.

In order to maintain a constant pressure in the reaction ves-' sel theinert gas has to be conducted away. For this purpose it is known toprovide an outlet for this inert gas in the upper side of the container,where a gas bubble is formed, said outlet having a closing member whichpermits regulation of the pressure in the vessel.

This construction has the disadvantage that when the liquid in thevessel fluctuates or the position of the vessel changes the liquid maycover the outlet. In order to prevent the liquid from penetrating intothe outlet, the closing member has to be shut. For conducting away theinert gas in spite of the above problem, a further outlet free of theliquid has to be opened. For this purpose a control-member and aplurality of required closing members has to be employed which causethis system to be expensive and sensitive to disturbances.

The invention has for its object to provide a heating system of the kindset forth in which the outlet of the supplied inert gas is substantiallyindependent of the position of the reaction vessel and of anyfluctuations of the liquid.

For this purpose the heating system in accordance with the invention ischaracterized in that the reaction vessel accommodates a centrifugecapable of producing at least locally a rotation of the liquid, whilethe outlet of inert gas opens out in the vicinity of the rotary shaft ofthe centrifuge.

By centrifuging the liquid with the inert gas a gas bubble is formedaround the rotary shaft of the centrifuge, since the gas has aconsiderably lower weight than the liquid. By having the outlet open outat the place of this gas bubble, the gas can be conducted away.Obviously independent of the position of the vessel the gas bubble isconstantly located around the rotary shaft of the centrifuge so that itany position of the vessel the gas can blow away through said outlet.

In connection with the present application the term centrifuge" has todenote a device comprising a plurality of bladeshaped members arrangedaround a rotary shaft capable of rotating the liquid around the rotaryshaft.

In order to avoid expulsion of liquid at too low a speed of thecentrifuge, that is to say at the start and at the stop, when it is nolonger certain whether the gas bubble is really formed, a furtherclosing member may be provided at the area of the out-let opening forthe inert gas, while a control-member is provided for opening saidclosing member when the operational speed of the centrifuge is attained.

In a further advantageous embodiment of the heating system in accordancewith the invention the inert gas out-let includes a liquid separator anda separator for vaporous metal and/or salt particles between the furtherclosing member and the controllable stop valve. The inert gas conductedaway is thus effectively purified so that it may be fed back to thesecond container, for example, by means of a compressor.

In another embodiment of the heating system in accordance with theinvention, in which the reaction vessel is formed by a circular channeland which comprises a pump for circulating the liquid, the supply ductof the oxidizing agent and the inert gas opens out at a place of thecirculating channel is located in front of the centrifuge, viewed in thedirection of flow of the liquid.

The invention will be described more fully with reference to thedrawing.

FIGS. 1 and 2 show schematically and not to scale two embodiments ofheating systems.

Referring to FIG. 1, reference numeral 1 designates the cylinder of ahot-gas engine, in which a piston 2 and a displacer 3 are adapted tomove. The piston 2 and the displacer 3 are connected by a piston rod 4and a displacer rod 5 respectively with a driving gear (not shown). Acompression space 6 is provided between the piston 2 and the displacer 3and communicates through a cooler 7, a regenerator 8 and a heater 9 withan expansion space 10. The heater 9 is formed by a crown of pipes 11,communicating at one end with the regenerator 8 and at the other endwith an annular channel 12 and by a crown of pipes I3, located betweenthe pipes 11, and connecting the annular channel 12 with the expansionspace 10.

The heater 9 is arranged in a reaction vessel 15 containing a liquidmixture of mainly Li and Ca. The vessel 15 accommodates a pump 16 whichis coupled through a shaft 17 with an electric motor 18. The pump 16causes the liquid in the vessel to circulate and a guiding partition 19conducts the flow of liquid in the direction of the arrow towards theheater 9, from which the liquid flows back to the suction side of thepump.

A reservoir 21 contains an oxidizing agent, preferably SP andcommunicates through a duct 22 including a controlvalve 23, with aplurality of supply ducts 24, only two of which are shown for the sakeof clarity.

There is furthermore provided a reservoir 25 containing an inert gas,for example, argon. The reservoir 25 communicates through a duct 26including a control-cock 27 also with the supply ducts 24.

When the stops 23 and 27 are opened, the oxidizing agent and the inertgas flow into the vessel 15. The oxidizing agent reacts immediately withthe metal contained therein so that solid and/or liquid salts are formedwhile heat is developed. The developed heat is given off to the workingmedium of the hot-gas motor which traverses the heater 9. The inert gasis not affected and if no outlet were provided for this medium, a risein pressure would be produced in the vessel 15. A centrifuge 30, formedby a plurality of blades connected with the rotor of the pump 16,rotates the mixture of liquid and inert gas. Owing to the difference inspecific weight a gas bubble is formed around the shaft 17 at 31. Theshaft 17 has a channel 32, which opens out at 31 and at the other end ina space 33. The space 33 accommodates a plurality of plates 34, againstwhich collides the inert gas conducted away so that any liquid particlescarried along by said medium are separated out. The separated liquid isleft in the space 33. The space 33 communicates with a vapor separator35, which is cooled so that the inert gas is cooled and any vaporousmetal or salt particles which may be carried along will condense and becollected. The vapor separator 35 communicates through a duct 36including a control-cock 37 with the suction side of a compressor 38,which compresses the inert gas and feeds it back into the reservoir 25.

The channel 32 in the shaft 17 can be closed by a lap 40, the stemofwhich is formed by the shaft 17 and which co-operates with anelectro-magnet 41. The electro-magnet is controlled by a centrifugalswitch 42 so that, when a given operational speed is attained, themagnet 41 is energized and the flap is opened.

The heating system operates as follows. In the first place the metalmixture in the vessel 15 is melted, for example, by means of an electricheating device (not shown). Then the control-cocks 23 and 27 are openedso that oxidizing agent and inert gas flow into the vessel 15. Theelectric motor 18 is energized so that the pump 16 and the centrifuge 30become operative. When the operational speed is attained, thecentrifugal switch 42 causes the electro-magnet 41 to be energized sothat the flap 40 is opened. In this way liquid is prevented from flowingout of the vessel 15 into the space 33 when the flap is openedprematurely, that is to say at too low a speed of the centrifuge 30,when no gas bubble has yet been formed. By means of the control-cock 37,a given desired pressure is maintained in the space 33 so that, when thepressure in the vessel 15 increases slightly, inert gas flows throughthe channel 32 into the space 33 and from there through the vaporseparator 35 and the compressor 38 back into the reservoir 25.

In this way an outlet of inert gas is obtained, which is substantiallyindependent of the position of the heating system. Thus a constantpressure is ensured in a fairly simple manner. Owing to this constantpressure cavitation phenomena and the associated noise in the pump andin the reaction zone are completely suppressed, while the supply ofoxidizing agent can always be performed against the same pressure.

Although in the device shown in FIG. 1 the pump and the centrifuge arecombined, it will be obvious that separate structures thereof are alsopossible under given conditions.

FIG. 2 shows a modified embodiment of the device of FIG. 1 schematicallyand not to scale. The reaction vessel 15 communicates through an outletduct 50 and a supply duct 51 with a outer vessel 52 containing the samemetal mixture as the reaction vessel 15. Since the outlet duct 50communicates with the compression side of the pump 16, and the supplyduct 51 with the suction side of the pump, a flow of liquid willconstantly pass through the outlet duct 50 to the spare vessel 52, andthrough the supply duct 51 a flow of liquid will constantly pass to thereaction vessel 15. Resultant salts will be carried along by the flowthrough the outlet duct 50 out of the reaction vessel 15, which saltssettle down in the spare vessel 52 due to their higher specific weight.The flow through the supply duct 51 will have a poor salt content sothat in the reaction vessel 15 a low, constant concentration of saltswill be found which is a guarantee for satisfactory reaction conditions.

Otherwise the device is constructed and operates like that shown in FIG.1 so that a detailed description thereof may be dispensed with.

What is claimed is:

1. A heating system for producing heat by the exothermic reaction of anoxidizing agent and re-actant material comprising:

a. a reaction vessel for containing a quantity of said reactant materialwhich is liquid at the operational temperature of the system,

b. a first reservoir for containing a quantity of said oxidizing agent,

c. first supply duct means for conveying the oxidizing agent from thefirst reservoir to the vessel,

d. means for regulating the flow in the first supply duct means,

e. a second reservoir for containing a quantity of gas inert to thereactant material and to the oxidizing agent, second supply duct meansfor conveying the inert gas from the second reservoir to the firstsupply duct,

g. inert gas discharge means for discharging inert gas from the vesseland for controlling said discharge, including a centrifuge with a shaftone part thereof being rotatable in the liquid within said vessel,gas-collection means in the vicinity of said shaft, and out-let ductmeans communicating gas from the collection means out of the vessel,whereby liquid is driven by the centrifuge outward from the shaft andthe inert gas is driven inward to the gas-collection means anddischarged via the out-let means.

2. Apparatus according to claim 1 wherein said reactant material is atleast one of the group comprising Li, Ca, Na, K, Mg, Al, and rare earthmetals, and the oxidizing agent is a halogen or halide such as sulfurhexafluoride (SP 3. Apparatus according to claim 2, further comprisingmeans driven by the centrifuge for opening said gas-discharge means andpermitting same to remain open for operation only after the centrifugeshaft has reached a predetermined minimum speed of rotation.

4. Apparatus according to claim 2 further comprising means forseparating liquid from the inert gas being discharged.

5. Apparatus according to claim 1 wherein said inert-gas discharge meansincludes a discharge chamber, and wherein said shaft has a hollowportion with axially spaced apertures one of which communicates with theliquid in said vessel and the other communicates with said chamber,whereby gas collected by the gas-collection means flows into the chamberbefore discharge via said out-let duct.

6. Apparatus according to claim 5 further comprising means formed astransversely extending plates in said gas-discharge chamber againstwhich discharge gas collides for separating liquid particles carried bythe gas from being discharged therewith.

7. Apparatus according to claim 3 further comprising means between thegas-discharge means and the second reservoir, for condensing and thenseparating from the discharged gas unwanted materials such as vaporousmetal and salt particles.

8. Apparatus according to claim 1 wherein the reaction vessel inoperational orientation has upper and lower parts, the apparatus furthercomprising an outer vessel surrounding the reaction vessel andcontaining the same reactant material as the reaction vessel, and havinga lower part situated below that of the reaction vessel, and a feederduct and an exhaust duct through which said material is flowablerespectively from the exhaust duct into the outer vessel where theydescend to the lower part thereof, and other liquid reactant material inthe outer vessel absent reaction products flows via the feeder duct intothe reaction vessel. the outer vessel to the reaction vessel andconversely, whereby 5 reaction products formed in the reaction vessel,are flowed via

2. Apparatus according to claim 1 wherein said reactant material is atleast one of the group comprising Li, Ca, Na, K, Mg, Al, and rare earthmetals, and the oxidizing agent is a halogen or halide such as sulfurhexafluoride (SF6).
 3. Apparatus according to claim 2, furthercomprising means driven by the centrifuge for opening said gas-dischargemeans and permitting same to remain open for operation only after thecentrifuge shaft has reached a predetermined minimum speed of rotation.4. Apparatus according to claim 2 further comprising means forseparating liquid from the inert gas being discharged.
 5. Apparatusaccording to claim 1 wherein said inert-gas discharge means includes adischarge chamber, and wherein said shaft has a hollow portion withaxially spaced apertures one of which communicates with the liquid insaid vessel and the other communicates with said chamber, whereby gascollected by the gas-collection means flows into the chamber beforedischarge via said out-let duct.
 6. Apparatus according to claim 5further comprising means formed as transversely extending plates in saidgas-discharge chamber against which discharge gas collides forseparating liquid particles carried by the gas from being dischargedtherewith.
 7. Apparatus according to claim 3 further comprising meansbetween the gas-discharge means and the second reservoir, for condensingand then separating from the discharged gas unwanted materials such asvaporous metal and salt particles.
 8. Apparatus according to claim 1wherein the reaction vessel in operational orientation has upper andlower parts, the apparatus further comprising an outer vesselsurrounding the reaction vessel and containing the same reactantmaterial as the reaction vessel, and having a lower part situated belowthat of the reaction vessel, and a feeder duct and an exhaust ductthrough which said material is flowable respectively from the outervessel to the reaction vessel and conversely, whereby reaction productsformed in the reaction vessel, are flowed via the exhaust duct into theouter vessel where they descend to the lower part thereof, and otherliquid reactant material in the outer vessel absent reaction productsflows via the feeder duct into the reaction vessel.